What the numbers mean at the wheel
Throwing size
At 11% total shrinkage, a form that must finish at 10 cm is thrown at 11.24 cm; a 4-inch mug is thrown at about 4.49 in. Half an inch of the pot disappears in the kiln.
How vitrified
2% absorption at cone 10. Below about 1% is fully vitrified stoneware or porcelain; 1–3% is typical functional stoneware; earthenware sits well above.
Clay for a batch
Fifty 450 g mugs with 10% trim waste need about 24.8 kg (55 lb) of clay — 2 boxes of 50 lb. Same for any body; what changes is how much of each mug ends up on the shelf.
Comparable bodies
Bodies in the same firing range with the closest published shrinkage and absorption — starting points for a substitute, never a drop-in. Test.
| Body | Maker | Cone | Shrink. | Absorp. |
|---|---|---|---|---|
| Ws-10WC387 | Laguna Clay | cone 10 | 11% | 1.5% |
| Elaine's Crystal Porcelain108950 | Sheffield Pottery | cone 10 | 11% | 2% |
| Stoneware119 | Standard Ceramic | cone 6 – 10 | 12% | 2% |
| Big RedWC372 | Laguna Clay | cone 10 | 10% | 1.75% |
| Half & HalfWC382 | Laguna Clay | cone 10 | 10% | 1.7% |
| GraniteWC885 | Laguna Clay | cone 10 | 11.8% | 1.4% |
Questions
- How much does Porcelain shrink?
- Sheffield Pottery publishes 11% total shrinkage at cone 10 — so a form that must finish at 10 cm is thrown at about 11.24 cm. Batches vary; measure a test tile from your own bag before committing a production run.
- What cone does Porcelain fire to?
- Sheffield Pottery rates it at cone 10. Fired above its range a body can slump or bloat; fired below it, it stays porous and glaze fit is unpredictable.
- Is Porcelain food safe?
- Food safety is a property of the fired glaze and the fit between glaze and body, not of the clay alone. A well-vitrified body (low absorption) with a stable, tested glaze is the usual functional combination; test your own.
Working with clay generates respirable silica dust. Wet-clean, ventilate, and wear a NIOSH-approved respirator for dry work; read the manufacturer's SDS for this body.
This information is provided for planning purposes and is derived from publicly available sources including OSHA regulations, NIOSH guidance, and manufacturer safety data sheets. It does not constitute professional safety advice. Consult your material suppliers' SDS documents and applicable local regulations for authoritative safety guidance.
Sources. Specs are the manufacturer's published values, read from the product page on 2026-08-17; nothing else on that page is reproduced. Throwing sizes and batch weights are computed by Claybench with the same formulas as our free shrinkage and clay weight calculators.
Claybench keeps this body's shrinkage on every form you plan
Add a clay body once; throwing sizes, drying times and clay-per-batch follow it through the studio.